This invention relates to a motor operator, and, more particularly, to a motor operator for circuit breakers.
It is known in the art to provide molded case circuit breakers for electrical systems. The circuit breaker is operative to disengage the electrical system under certain operating conditions. The use of motor operators to allow the motor-assisted operation of electrical circuit breakers is well known. The motor operator allows the circuit breaker to be operated remotely and to be opened, closed or reset after tripping of the circuit breaker.
The motor operator is typically secured to the top of a circuit breaker housing. A lever within the motor operator mechanically interacts with a circuit breaker operating handle, which extends from the circuit breaker housing. The lever is operatively connected to a motor within the motor operator. The motor drives the lever, which, in turn, moves the operating handle to operate the circuit breaker. The operating handle is moved between xe2x80x9conxe2x80x9d, xe2x80x9coffxe2x80x9d, and xe2x80x9cresetxe2x80x9d positions, depending on the rotational direction of the motor.
A plurality of buttons external to the motor operator controls electrical current to the motor. The rotational direction of the motor is changed depending on which of these buttons is selected by operating personnel. Thus, the operating personnel can select one button to place the operating handle in the xe2x80x9conxe2x80x9d position, and another button to place the operating handle in the xe2x80x9coffxe2x80x9d or xe2x80x9cresetxe2x80x9d positions.
When the handle is moved to the xe2x80x9conxe2x80x9d position, electrical contacts within the circuit breaker are brought into contact with each other, allowing electrical current to flow through the circuit breaker. When the handle is moved to the xe2x80x9coffxe2x80x9d position, the electrical contacts are separated, stopping the flow of electrical current through the circuit breaker. When the handle is moved to the xe2x80x9cresetxe2x80x9d position, an operating mechanism within the circuit breaker is reset, as is necessary after the operating mechanism has tripped in response to an overcurrent condition in the electrical circuit being protected by the circuit breaker.
Due to the mounting of the motor operator onto the case of the circuit breaker, excessive lost motion can result between the motor operator and the circuit breaker under extreme operational loads. Excessive motion caused by the motor operator not being rigidly secured to the circuit breaker can result in excessive lost motion between the motor operator and the circuit breaker such that the motor operator is unable to sufficiently move the handle in order to turn the circuit breaker to the desired position (ie. off, on, reset).
The above discussed and other drawbacks and deficiencies are overcome or alleviated by an assembly for connecting a motor operator mechanism to side frames of a circuit breaker operating mechanism. The assembly comprising a plate connected between the side frames of the operating mechanism and a bracket portion secured to the plate and engages the motor operating mechanism. The bracket portion couples and aligns the motor operator mechanism and the circuit breaker operating mechanism.